Estrogen receptor alpha (ERa) is a member of the nuclear receptor (NR) family. NR is one of the transcription factors that regulate target gene expression. ERa plays an important role of reproduction in physiological functions, therefore, the study of chemical binding to ERa is very useful for research of endocrine disrupting chemicals (EDCs) and drug screening.
NR activation before gene expression consists of 3 steps.
Step1: Ligand binding to NR induces conformational change of NR
Step2: Coactivator is recruited to NR-ligand complex
Step3: Other transcriptional factors are recruited to NR-ligand-coactivator complex
Competitive binding assay detects only the ligand-binding to NR, whereas RCAS detects NR-ligand-coactivator complex. Therefore you can predict the characteristic of your test samples more accurately using this RCAS kit (i.e. both agonist and antagonist for ERa can be detected.).